JP2525844C - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial Application Field] The present invention moves a relative position between an original film, a lens, and a photosensitive material, and forms an image on the photosensitive material at a predetermined magnification by light transmitted through the original film. The present invention relates to a method of correcting a focus position of a machine. [Prior art] Conventionally, when printing a photograph on a photosensitive material, a magnification of an image to be printed on the photosensitive material with respect to an image of an original film such as a negative film is determined using a enlarger, and a head of the enlarger is determined based on the magnification. After moving up and down with respect to the enlarger installation surface,
Exposure is performed. Such enlargers include a type in which a light source is arranged in the apparatus main body, a light beam is irradiated from below the negative film, and the photosensitive material is exposed through a lens arranged in a head (a so-called inverted type). A light source and a lens are disposed on the head, a negative film is interposed between the light source and the lens, a light beam is irradiated from above the negative film, and the transmitted light is passed through the lens onto a table of the apparatus body. There is a type that irradiates and exposes the arranged photosensitive material (a so-called upright type). Negative film is usually loaded in a negative carrier,
When the exposure with one negative film is completed, the worker removes the negative carrier from the enlarger, replaces it with the next negative film, and mounts the negative film again. . By the way, in such a photo enlarger, when the enlargement magnification is changed, the head is moved in the optical axis direction (up and down direction with respect to the apparatus installation surface). In focusing, the lens is moved in the vertical direction. A ball screw is applied to the vertical drive mechanism for performing such movement. In this ball screw drive, a male screw (a side of a spindle installed parallel to the moving direction) and a female screw (a side of a member to be moved such as a head) are screwed together via a ball, and are accurately covered by rotation of the spindle. The moving member can be moved in the axial direction of the support shaft. A pulse motor is usually attached to one end of the spindle, and by sending a predetermined pulse signal to the pulse motor, the driving force of the rotating shaft of the pulse motor is transmitted to the spindle, and the spindle is rotated. It has become. However, even with such a highly accurate ball screw, there is a slight error (a pitch error in the axial direction), and the error increases as the overall length of the screw increases. For this reason, conventionally, an error with respect to the entire length of the male screw is actually measured, and the number of pulses supplied to the pulse motor is always uniformly corrected. In other words, the actual value of the error is 1 mm when the male screw of the support shaft has a total length of 1000 mm, and the movement distance is calculated as {5 mm + (1 × 5/1000)} when calculating the number of pulses when moving by 5 mm. In this way, the error can be corrected. [Problems to be Solved by the Invention] However, the error does not occur uniformly over the entire length of the male screw. Even if the error is 1 mm as a whole, there is an error of 0.2 mm in a part. However, since there is no error in the other part, if the error is corrected evenly, there may be places where the accuracy decreases. Therefore, in such error correction, the focus position may be inappropriate. As a related technique, there has been proposed a technique for calculating a moving distance with high accuracy by automatically resetting position detection data when a moving platform (a lens platform, a document platform, etc.) reaches a reference point. (See JP-A-53-97148)
. According to this, the accumulated error at the time of movement can also be prevented. However, the present invention has a problem that an error occurs in the focal length (focus) at each magnification, not the moving amount to each designated magnification, and the above-described prior art cannot solve this problem. . In consideration of the above facts, the present invention provides an original film,
In changing the relative positions of the lens and the photosensitive material, it is possible to correct a focus error due to a small error at each designated magnification, and to obtain a focus position correction method for a photo enlarger capable of improving focus accuracy. That is the purpose. [Means for Solving the Problems] The focus position correcting method for a photograph enlarger according to the present invention is a method for controlling the amount of movement of an original film, a lens and a photosensitive material in the axial direction of a support shaft by rotating the support shaft. Possible bo
It is relatively moved by Lumpur screw mechanism, a autofocus method for correcting photographic enlarger for imaging to the photosensitive material at a predetermined magnification by transmitted light transmitted through the original film, a plurality of magnifications for error correction The difference between the calculated relative position calculated for each of the plurality of magnifications based on the specified magnification and the actual relative position where the focus at the magnification is appropriate is stored in advance, and the photosensitive material is stored. When the position is changed to the calculated relative position based on the specified magnification for forming an image, the stored difference is read based on the specified magnification, and the moving amount is corrected based on the read difference. , And is positioned at an actual relative position. [Operation] In the present invention, the relative positions of the original film, the lens, and the photosensitive material are actually moved based on a plurality of specified magnifications, and an error between the relative position and the focus appropriate position is calculated for each of the specified magnifications. Since the correction is performed, the accuracy of the focus position can be improved. The error applied to the correction of the moving amount may be stored at the time of the shipping inspection of the photo enlarger, or, for example, the above correction program may be stored in a control device in the photo enlarger main body. By doing so, it is possible for the user to perform the operation freely. Further, in the present invention, the correction amount (difference) is obtained for each of a plurality of magnifications and stored as a difference between the respective magnifications. This is because interpolation at a magnification other than the specified magnification is easily performed. For example, if an appropriate relative position at a directly designated magnification is stored, the movement amount at a magnification other than the designated magnification cannot be corrected. That is, if the correction amount is stored, the correction amount at the magnification before and after the correction amount can be predicted, and continuity can be obtained. Embodiment A photo enlarger to which the present invention can be applied will be described in detail below with reference to the drawings.
As shown in FIG. 1, a so-called upright type photo enlarger body 10 has a support (not shown).
Inside, two support shafts 12 and 14 are erected in parallel with each other.
, 14 are screwed with a head portion 16 for adjusting the printing magnification and a focus adjusting portion 18, respectively. Pulse motors 2 are provided at the bases of the support shafts 12 and 14, respectively.
Rotation shafts 0 and 22 (not shown) are fixed coaxially.
The support shafts 12 and 14 are rotated by the driving force of 2. Here, when the respective support shafts 12 and 14 rotate, the head portion 16 or the focus adjustment portion 18 is moved in the axial direction of the support shafts 12 and 14 independently. The head section 16 includes a lamp house section 24 and a negative carrier loading section 26. In the lamp house section 24, a halogen lamp 28 and a dimming filter 30 are sequentially arranged. This dimming filter 30 includes yellow (Y), magenta (M),
Each filter is composed of cyan (C) filters.
Are movable independently in a direction perpendicular to the optical axis. A negative carrier 34 is loaded in the negative carrier loading section 26, and a negative film 36 is held in the negative carrier 34. The head portion 16 and the focus adjustment portion 18 are connected by a bellows 38, so that the inside of the head portion 16 and the inside of the focus adjustment portion 18 are in communication with each other and are shielded from the outside, and both can be approached and separated. A focusing lens 40 is provided at the lower end of FIG.
Is installed. The light beam from the halogen lamp 28 via the light control filter 30, the negative film 36, and the enlargement lens 40 forms an image on the photographic paper placement section 44 on the table 42 of the enlarger body 10, and the worker sitting on the chair 46 The projection image of the negative film 36 is configured to be visible. Further, an operation panel 50 is provided on the table 42 of the enlarger body 10, and is configured so that input of measurement data, setting of a set magnification, and trimming can be performed from the operation panel 50. When the photographic paper 52 is placed on the placement section 44 of the table 42, the photographic paper 5
2, an image of the negative film 36 is formed when the halogen lamp 28 is turned on. The operation panel 50 is connected to a microcomputer 54 having a RAM, a ROM, and a CPU. Further, the pulse motors 20 and 22 and the drive unit 32 are connected to the microcomputer 54, and output a drive signal based on an instruction from the operation panel 50. In the RAM of the micro computer 54, a movement control program for the head section 16 and the focus adjustment section 18 based on the magnification and a correction amount for an error caused by automatic positioning between the position of the head section 16 and the position of the focus adjustment section 18 are obtained. An error measurement program is stored, and an error correction amount based on the set magnification is stored in the RAM by the error measurement program before starting the enlargement operation. Therefore, when the movement control program is started, the error correction amount stored in the RAM is read out, and the positions of the head section 16 and the focus adjustment section 18 are corrected, so that accurate positioning is performed. . The operation of the present embodiment will be described below. First, an error measuring routine of the male screw of the spindles 12 and 14 will be described. The program of the error measurement routine is stored in a control device that is separate from the photo enlarger at the time of shipping inspection on the manufacturer side, and is stored in the micro computer 54 in the photo enlarger main body 10.
May be connected and controlled, or may be stored in advance in a ROM in the microcomputer 54 so that the user can freely perform the control. First, in step 200, magnifications M ₁ , M ₂ ,... Mn are set. Moves the head unit 16 based on the magnification M ₁ that is set in the following in step 202 above, to position. Here, as shown in FIG. 5, the magnification M ₁ is table out with length between the negative film 36-enlarger lens 40 (a ₁₎ and enlarger lens 40- length between the printing paper 52 (b ₁₎ (See equation (1)), and the relationship between the focal length f and the a ₁ and b ₁ is represented by equation (2). M ₁ = b ₁ / a ₁ (1) 1 / f = (1 / a ₁ ) + (1 / b ₁ ) (2) Therefore, the origin L ₀ is determined in advance, and Assuming that the distance from L ₀ to the photographic paper 52 is L (invariant value), the distance L ₁ from the origin L ₀ to the position of the negative film 36 can be calculated from the above equations (1) and (2). The sum of the distance L ₁ and the distance a ₁ to 1 interval, the next step 204, the automatic positioning position of the lens 40 with Pintochiyato fixed in Maniyuaru, in step 206 the amount of the modified The error (| a ₁ −a ₁ ′ |) is stored in the RAM of the microcomputer 54 together with the set magnification. In this case, the number of pulses driven at the time of correction can be obtained by dividing the correction amount by the distance traveled by one pulse (the number of pulses for one rotation of the screw pitch / screw). Next, in step 208, it is determined whether or not the magnification setting for error correction has been completed. This can be recognized by, for example, operating the keys on the operation panel 50. The larger the magnification for error correction is, the better, but usually about 5 types of 1 ×, 3 ×, 5 ×, 7 × and 9 × are preferable. When a new magnification M ₂ end key is not operated in step 208 is set, repeat the process proceeds to step 200 to Mn, if the end key is operated this routine ends. Next, the control of the exposure processing of the photo enlarger applied to the present embodiment will be described with reference to the flowchart of FIG. First, when the negative carrier 34 is loaded into the negative carrier loading section 26 in step 100 (this detection may be performed by operating a predetermined key of the operation panel 50 after the negative carrier is loaded, or a limit switch or the like may be applied to the negative carrier loading section 26. The determination may be made based on a signal from the limit switch.) Then, the process proceeds to step 102, and the position of the negative film 36 is confirmed. This is because the negative image is formed on the placement unit 44 by turning on the halogen lamp 28 in a state where the photographic paper 52 is not placed on the placement unit 44, so that the operator can easily confirm the negative image. When the position of the negative film 36 is confirmed, the operation proceeds to step 104 and the operation panel 5 is operated.
The magnification is set by operating the key 0, and then the number of prints is set in step 106. When these settings are completed, the photographic paper 52 is placed on the placement unit 44, and the process proceeds to step 108, where the pulse motor 20 is driven based on the set magnification to start moving the head unit, and the pulse motor 22 is also moved. When driven, the focus adjustment unit 18 is moved simultaneously with the head unit 16. The pulse motors 20 and 22 are driven according to the number of pulses supplied from the microcomputer 54. At this time, the microcomputer 54 calculates the optimum focus at that time based on the continuously changing magnification, corrects the drive signal to the pulse motor 22, and moves the pulse motor 22 in a state where the focus is always maintained. Here, as shown in FIG. 4, the microcomputer 54 determines the amount of movement (section length) of the head unit 16 to a predetermined position based on the set magnification according to the formula (1) and (2).
The error correction amount at this magnification is read from the RAM (step 150).
Step 152). In the next step 154, the number of pulses supplied to the pulse motor is corrected based on the read error correction amount, and the pulse motors 20 and 22 are driven based on the corrected value (step 156). In the next step 109, an exposure process is performed, and the image of the negative film 26 is formed on the photographic paper 52. When the exposure control is completed, the process proceeds to step 110, where it is determined whether or not the set predetermined number has been reached.
Then, the exposure processing is performed. If the number has reached the predetermined number, the process proceeds to step 114 to continuously determine whether or not the exposure processing has been completed. If a negative determination is made in step 114, it is determined that exposure control with different magnification settings is to be performed on the same image, and the flow advances to step 102 to repeat the above processing. Also,
If an affirmative determination is made, it is determined that the exposure processing has ended, and this routine ends. In the present embodiment, as the plurality of magnifications, the five commonly used types (1 ×, 3 ×, 5 ×, 7 ×, 9 ×) are selected, but the number n of selections is not limited to this. Absent. That is, as the number of selections n increases, a correction amount most suitable for the magnification can be obtained. When a magnification other than the selected magnification is specified, the correction amount of the closest selected magnification may be applied, or the correction amount may be predicted based on this correction amount. Further, when there is some correlation between the magnification-correction amount characteristics, interpolation may be performed based on correction amounts at a plurality of approximate magnifications (stored as a map). [Effects of the Invention] As described above, the focus position correcting method for a photo enlarger according to the present invention uses the basic control at the time of setting the magnification to change the relative positions of the original film, the lens and the photosensitive material at each specified magnification. This makes it possible to correct that the focus becomes loose due to the small error in the above, and has an excellent effect that the focus accuracy can be improved.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a schematic diagram of a photo enlarger to which the present invention can be applied, FIG. 2 is a flowchart showing an error measuring routine of the present embodiment, and FIG. FIG. 4 is a flowchart showing a control routine, FIG. 4 is a flowchart showing movement control to a set magnification position,
FIG. 5 is a schematic view showing the positional relationship between the negative film, the enlargement lens, and the photographic paper. DESCRIPTION OF SYMBOLS 10 ... Enlarger body, 16 ... Head part, 18 ... Focus adjustment part, 36 ... Negative film, 54 ... Microcomputer.

Claims (1)

Claims: (1) An original film, a lens, and a photosensitive material are rotated by rotating a support shaft so that an axis of the support shaft is provided.
The movement amount control capable ball screw mechanism in the direction moved relative to a autofocus method for correcting photographic enlarger for imaging to the photosensitive material at a predetermined magnification by transmitted light transmitted through the original film, A plurality of magnifications for error correction are designated, and a difference between a calculated relative position calculated based on each of the designated magnifications for each of the plurality of magnifications and a real relative position at which the focus at the magnification is appropriate is determined. When the position is changed to the calculated relative position based on the specified magnification for forming an image on the photosensitive material,
Reading the stored difference based on the designated magnification, correcting the moving amount based on the read difference, and positioning the actual position relative to the actual position. Method.